Fire alarm



April 10, 1928.

1,665,956 5. GIANGRASSO FIRE ALARM Filed Aug. 28. 1926 2 Sheets-Sheet l @igi.

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s. GIANGRASSO FIRE ALARM Filed Aug. 28. 1926 2 Sheets-Sheet 2 CELLULOH) Salvatore Giaqqrasso.

Patdnted Apr. 10, 1928.

. UNITED STATES I 1,665,956 OFFICE.

PATENT SALVATORE GIANGBASSO, 01' YOBTLAND, mam.

mam.

Application fled August 28, 1926. Serial No. 188,884.

A further object of the invention isto provide afire alarm wherein a single audible signal in the form of an electric bell is in cir- 1 cuit with a source of electric energy and a series of switch devices normally retained in open gpsition by an inflammable fuse which upon eing ignited releases the switch for the closing of a circuit and the ringing of the bell, the control device and switch embodying novelty in the assembling thereof.

With the above and other Qb'eets in view that will become apparent as t e nature of the invention is better understood, the same consists in the novel form, combination and arrangement of parts and in the details of construction hereinafter -'more fully described, shown in the accompanying drawings and claimed.

In the drawings wherein like reference characters are employed to designate corresponding parts throughout the .several views,

Figure 1 shows a wall box, partly broken away to show the inclosed battery and bell as with electric wires extending therefrom to the switch control device that is illustrated in side elevation as being suspended from a room ceilin Figure 2 1s a top plan view of the switch control device;

Figure 3 is a bottom plan view of the switch control device;

Figure 4 is a horizontal sectional view taken on line 44 of Figure 5;

Figure 5 is a longitudinal sectional view of the switch control device showing the spring pressed button switch in itsopen position and the tensioned plunger for closing the switch held in set position by an inflammable celluloid cap;

Figure 6 is a bottom plan view, similar to Figure 3 with the switch terminals removed from the control device;

Figure 7 is a bottom plan view of another as form of switch control device;

Figure 8 is across sectional view taken on line 8-8 of Figure 7; and

Figure 9 is a diagrammatic view showing the battery, manual switch, bell and a plurality of switch control devices in circuit with the bell and battery.

It being understood that the switch control devices include as a part thereof an inflammable element, said control devices may be positioned at the desired location such' as in proximity of the wood work of a room m with all of the switch control devices in circuit with a battery and bell, there is illustrated a wall box 1 containing a battery 2 and a hell 3. As shown in Figure 1, a single switch control device 4 is in circuit with p the battery 2 and bell 3 by the provision of the wire 5 extending from one pole 6 of the batte to one of the switch contacts 7 while the ot er wire 8 leads from the other switch contact 9 to the other pole 10 of the battery, it being understood that the bell 3 is interposed in the wire 8 and undercontrol of the manually operable switch 11.

The switch control device 4, any number of which may be provided as diagrammatically illustrated in Figure 9 and interposed in the circuit wires 5 and 8, comprises a base late 12, preferably of the form illustrated in igures 2 to 5that is anchored as at 13 to supporting surfaces 14 that may represent either walls or ceilings, window or door frames or any other part of a building structure, it being noted that the main switch 11 is closed when the fire alarm is in such position while the switch of each control device 4 is open and is adapted to be closed for completing the circuit to sound the bell upon ignition of an inflammable substance, such as celluloid that forms a part of the switch control device. The base plate 12 is provided with an internally threaded opening that receives the enlarged externally threaded annular shoulder 14 of the tubular member 15 that is open at its outer end as shown in Figure 5, the shoulder 14 being enlarged and lying flush with opposite faces of the base plate 12. The end of the shoulder 14 at the wall contacting face of the base plate carries an inwardly directed annular flange 16 that is interrupted for a portion of its length as at 17 while an inwardly directed annular wall 17' is disposed at the opposite end of said shoulder 14.

An insulation strip 18 carries the contacts 1 sai 7 and 9 adjacent opposite ends to which the wires 5 and 8 are respectively attached, the insulation strip 18 belng set into the annular shoulder 14 by the provision of the cutaway ortion 17 of the flan e 16 and being therea er partially turned as its opposite ends disposed beneath said flange to prevent removal. A push button' 19 of the cupsha ed type is set into the annular shoulder as s own in Figure 5 while the spring 20 1nter sed between the insulation strip 18 and ush button normally separates the latter iiom the contacts 7 and 9 with the annular flange of the push button engaging the wall 17' to limit separating movement thereof.

The outer end of the tubular member 15 is internally threaded and receives the pipe section 21 while a plunger 22 is reciprocable in the'tubular member and pipe section. The inner end of the plunger 22 carries an annular shoulder 23 substantially contacting the inner face of the tubular member while said plunger contacts the inner face of the pipe section 21 to provide for a free reciprocating movement of said plunger. A. coil spring 23 incloses the plunger and engages at one of its ends the plunger shoulder 23 while the other end engages the inner end of the pipe section 21. It will therefore be seen from an inspection of Figure 5 that the action of the spring 23 normally supports the plunger in a direction toward the ush button 19 for the purpose of closing t e switch contacts 7 and 9.

To hold the plunger 22 spaced from the push button 19 against the tension of the spring 23 and also to permit thespring 20 to space the push button from the contacts 7 and 9, there is provided an inflammable device that is associated with the plunger 22, the construction of which is shown more clearly in Figure 5. The outer end of the pipe section 21 receives the cap 24 that is formed of celluloid or other inflammable material, the closed end of the cap 24 havin a relatively large opening 25 therein. stem 26 carried by the plunger 22 extends through the opening 25 and has a nut 27 threaded upon the outer end thereof, the edge of the nut engaging the closed end wall 2 1 of the cap 24 outwardly of the opening 25 for holding the plunger 22 partially extended against the tension of the spring 23.

When the celluloid cap 24 becomes ignited, the end wall 24: thereof will burn and the opening 25 being enlarged, the spring 23 removes the plunger 22 for operating the ush button 19 to close the switch contacts and 9 for sounding the bell 3.

A plurality of switch control devices are shown in Figure 9, the several push buttons being diagrammatically illustrated by the reference numerals 19 while t e contacts are designated bythe reference numerals '2" and a terminal annular shoulder on 9 respectively. With the wire diagram illustrated in Figure 9, it will be observed that when one of the push buttons 19 is moved into engagement with the adjacent contacts 7fland 9', the circuit will be completed for ringing the hell 3. After the alarm has been given, the circuit may be broken by the main switch 11.

A modified'construction of mounting the insulation late 18 in the base plate 12 is shown in igures 7 and 8 wherein the flange 16 of the annular shoulder carries a spring portion 17 that permits the insulation plate 18 to be snap ed into position.

From the a ove detailed description of the device, it is believed that the construction and operation thereof will at parent, and while there are herein shown and described the preferred embodiments of the present invention it is nevertheless to be understood that minor therein without departing from the spirit and scope of the invention as claimed.

What I claim as new is 1. A thermally controlled circuit closer comprising a switch and an inflammable device for holding the switch open and ada ted when ignited to permit closing of t 6 switch, said switch including an insulation strip, a pair of contacts carried thereby and a terminal push button for the contacts, the inflammable device comprising a tubular member, a reciprocating plunger therein, an annular shoulder on the end of the plunger adjacent the push button, a pipe section threaded ,into the outer end of the tubular member, a coil spring surrounding the plunger between theshoulder and pipe section, a cap-shaped inflammable element on the outer end of the pipe section, and a pin and nut connection between the plunger and inflammable element for normally holding the plunger inoperative with respect to the push button.

2. A thermally controlled. circuit closer comprising a switch and an inflammable device for holding the switch open and adapted when ignited to permit closing of the switch, said switch including an insulation strip, apair of contacts carried thereby and push button for the contacts, the inflammable device comprising a tubular member, a reciprocating plunger therein, an the end of the plunger adjacent the push button, a pipe section threaded into the outer end of the tubular member, a coil spring surrounding the plunger between theshoulder and pipe section, a cap-shaped inflammable element on the outerend of the pipe section, a pin and nut connection between the plunger and inflammable clement for normally holding the lunger inoperative with respect to the push utton, a base plate mounting for the tubular member, and an interlocking connection once be apbetween the tubular member and insulation a strip.

3. A thermally controlled circuit closer comprising a switch and an inflammable device for holdin the switch open and adapted when ignited to permit closing of the switch, said switch lincludin an insulation strip, a pair of contacts carried thereby and a terminal push button for the contacts, the inflammable device comprising a tubular member, a reciprocating plunger therein, an annular shoulder on the end of the plunger adjacent the push button, a pi e section threaded into the outer end of t e tubular member, a coil spring surrounding the plunger between the shoulder and pipe section, a cap-sha d inflammable element on the outer end 0 the pipe section, a pin and nut connection between the plun er and inflammable element for normally olding the hunger inoperative with respect to the push )utton', a base plate mounting for the tubular member, and an interlocking connection between the tubular member and insulation strip, including an annular shoulder on the tubular member having a clearance for one end of the insulation strip.

In testimony whereof I aflix my signature.

SALVATORE GIANGRASSO. 

